Process monitoring and adaptive control of a machine tool

1. A method, performed in a control system, wherein the control system includes a programmable logic control section configured to control operation of a machine and a numerical control section configured to control relative motion between a tool of said machine and a work piece, wherein the method comprises: evaluating an input signal, received by the programmable logic control section, in relation to a first condition, wherein the input signal includes information about a state of the tool or about a state of a subtractive process performed via interaction of the tool and the work piece; in response to the input signal satisfying the first condition, providing said information to the numerical control section as input to a current computer program being executed by the numerical control section without interrupting the current computer program; evaluating the input signal in relation to a second condition, which is different from the first condition; in response to the input signal satisfying the second condition; triggering interruption of the current computer program executed by the numerical control section; assigning another computer program in the numerical control section to be the executed by the control system; providing said information as input to the assigned computer program allowing the assigned computer program to distinguish between different states of the tool or the subtractive process; evaluating the input signal in relation to a third condition; and in response to the input signal satisfying the third condition, assigning at least a portion of a computer program in the programmable logic control section to be executed by the control system with said information as input.

2. The method of claim 1 , wherein the information included in the input signal indicates: tool breakage; tool wear; tool missing; work piece missing; wrong cutting data; a temperature to which the tool is subjected; a force to which the tool is subjected; tool vibration; process chatter; or a current geometry of the work piece.

3. The method of claim 1 , comprising, in response to the information included in the input signal, indicating a state from a set of predefined states: triggering interruption of a computer program including computer executable code executed by the numerical control section; assigning another computer program including computer executable code in the numerical control section to be the executed by the control system; and providing said information as input to the assigned computer program, wherein the set of predefined states includes: tool breakage; tool wear; tool missing; work piece missing; wrong cutting data; a temperature to which the tool is subjected exceeds a threshold; a force to which the tool is subjected exceeds a threshold; tool vibration exceeds at threshold; process chatter exceeds a threshold; or a current geometry of the work piece is within a tolerance.

4. The method of claim 3 , wherein the assigned computer program in the numerical control section includes instructions for controlling the machine to: discontinue a motion; retract the tool from the work piece; retract the work piece from the tool; replace the tool by a sister tool; move the tool towards a camera for evaluation; move the work piece towards a camera for evaluation; trigger motion of a camera for evaluation of the tool; trigger motion of a camera for evaluation of the work piece; or change cutting data.

5. The method of claim 3 , wherein the assigned computer program in the numerical control section is an editable numerical control program.

6. The method of claim 1 , wherein the assigned computer program in the numerical control section includes instructions for controlling the machine to: discontinue a motion; retract the tool from the work piece; retract the work piece from the tool; replace the tool by a sister tool; move the tool towards a camera for evaluation; move the work piece towards a camera for evaluation; trigger motion of a camera for evaluation of the tool; trigger motion of a camera for evaluation of the work piece; or change cutting data.

7. The method of claim 1 , wherein the assigned computer program in the numerical control section is an editable numerical control program.

8. The method of claim 1 , comprising, in response to the input signal satisfying the third condition: generating an intermediate signal by transforming at least part of the input signal; and assigning said at least a portion of a computer program including computer executable code in the programmable logic control section to be executed by the control system with the intermediate signal as input.

9. The method of claim 8 , wherein said at least part of the input signal includes bits jointly signaling said state of the tool or said state of a subtractive process performed via interaction of the tool and the work piece, and wherein the intermediate signal includes a plurality of bits independently signaling whether the state of the tool or the state of the subtractive process performed via interaction of the tool and the work piece coincides with respective predefined states.

10. The method of claim 1 , wherein the assigned program in the programmable logic control section is locked from editing.

11. A computer program stored on a non-transitory computer readable storage medium including computer executable code for performing the method as defined in claim 1 .

12. A computer program package stored on a non-transitory computer readable storage medium, the computer program package comprising: the computer program of claim 11 ; and a complementary computer program, for use in a monitoring system, wherein the monitoring system includes an input section for receiving data from at least the control system or the tool, and an output section for providing data to the control system, wherein the complementary computer program includes computer executable code for performing a complementary method comprising: obtaining an estimated state by estimating, based on data received by the input section, a state of the tool or a state of a subtractive process performed via interaction of the tool and the work piece; and providing information about the estimated state to the output section for transmittal, via said input signal, to the control system.

13. A non-transitory computer-readable storage means for storing the computer program and computer program package of claim 12 .

14. A control system comprising: a programmable logic control section configured to control operation of a machine; and a numerical control section configured to control relative motion between a tool of said machine and a work piece, wherein the programmable logic control section is configured to: receive an input signal including information about a state of the tool or a state of a subtractive process performed via interaction of the tool and the work piece; evaluate the input signal in relation to a first condition; in response to the input signal satisfying the first condition, provide said information to the numerical control section as input to a current computer program being executed by the numerical control section without interrupting the current computer program; evaluating the input signal in relation to a second condition, which is different from the first condition; in response to the input signal satisfying the second condition; triggering interruption of the current computer program executed by the numerical control section; assigning another computer program in the numerical control section to be the executed by the control system; providing said information as input to the assigned computer program allowing the assigned computer program to distinguish between different states of the tool or the subtractive process; evaluating the input signal in relation to a third condition; and in response to the input signal satisfying the third condition, assigning at least a portion of a computer program in the programmable logic control section to be executed by the control system with said information as input.

15. A system comprising: the control system of claim 14 ; and a monitoring system configured to: receive data from at least the control system or the tool; obtain an estimated state by estimating, based on the received data, a state of the tool or a state of a subtractive process performed via interaction of the tool and the work piece; generate said input signal based on the estimated state; and provide said input signal to the control system.